Resonance attachment for sound reproducing devices



y 3 A. E. TAUSCHER-ETAL 1,812,993

RESONANCE ATTACHMENT FOR SOUND REPRODUCING DEVICES Filed March 20, 193G Imfe ors 1 0118026? Patented July 7, 1931 UNITED STATES PATENT OFFICE ABNO E. TAUSCHER AND BENNO E. SCHULTZE, OF CHICAGO, ILLINOIS RESONANCE ATTACHMENT r03 SOUND nnrnonncme DEVICES Application filed March 20, 1980. Serial No. 437,456.

This invention has for its objects to provide new and useful improvements in sound reproducing devices such as the loud or dynamic speakers of radio wave receiving apparatus commonly known as radio sets for the purpose of securing more accurate reproduction and to reduce the harshness of reproduced sound waves of such apparatus, and improving the tone quality of the instrument.

More specifically, the object of the invention may be explained and defined as being intended to provide a series of sounding boards so relatively arranged and varied in dimensions as to be severally reponsive to sound waves of different registers to thereby harmonize low, middle and high register sound Waves to prevent some thereof being disproportionately loud or soft with respect to others except in so far as various notes are produced by voice, chorus, musical instrument or orchestra, etc.

A suitable embodiment of the invention is illustrated in the accompanying drawings wherein:

Fig. 1 is a side elevation and Fig. 2 is a front elevation of a loud or dynamic speaker constructed in accordance with the invention.

Fig. 3 is a fragmentary plan section of the same on the line 33 of Fig. 2.

Fig. 4 is a perspective view of a series of sounding boards or resonance elements detached from the cone of the instrument and seen from the rear or innermost portion thereof.

In the drawings there is shown the casing 1 of a sound reproducing structure of conventional type having an opening and to which the small end of a skeleton hollow truncated cone member 2 is suitably secured, said member 2 being provided with an annular flange 3 at its outer or mouth end.

Mounted within the member 2 is a conventional paper cone 4 which is of smaller diamingly supported in the member 2 by means of a washer 5 of very flexible material such as rubber or leather which bridges the annular space between the mouths of the members 2 and 4 and is preferably secured to the annular flange 3 of the former by means of a metal or other relatively inflexible ring or washer 6 which is bolted to the flange 3 and clamps the marginal portion of the Washer 5 against said flange.

The subject-matter of the present invention may best be defined as constituting an attachment for the conventional type of instrument above described and comprises a series of resonance plates which, in the instance illustrated, consists of an outer circular plate 7 an intermediate ring-plate 8 and a small diameter circular plate 9, all spaced from and parallel with each other, it being understood that the number, shape, and relative sizes and spacing apart of said plates all may be varied from the specific illustration without departing from the invention.

Preferably the plate 7 is of approximately the same diameter as the outer diameter of the flange 3 and is appreciably spaced from the latter. Said plate 7 is shown as provided with openings similar to those of violins but said openings are not essential and may be omitted.

The ring-plate 8 is of smaller diameter than the plate 7 and is preferably disposed so that its outer face is substantially flush with the outer end or rim of the member 4 the diameter of said plate 8 being such as to leave a free annular space between its circumferential edge and the mouth portion of said member 4.

The plate 9 is of such diameter and so spaced from the plate 8 as to provide a relatively wide annular space between its circumferential edge and the member 4.

The plates 7, 8, and 9 are secured together in any suitable manner as, for example, by means of the Z'brackets 1O bolted or otherwise rigidly secured to said plates, so that the several plates and brackets form a complete structure or attachment which is secured to the member 2 by means of bolts 11 and spacing sleeves 12, the bolts 11 being substituted for the short bolts usually employed to secure the ring or washer 6 inplace, sa d bolts 11 and'spacing sleeves 12 serving to secure the Z-brackets to the plate 7 and the ring 6 to the flange 3 and hold the entire set of plates 7, 8,, and 9 in proper position relatively to the member 4.

The said plates 7, 8, and 9 are preferably made of a suitable soft wood well varnished, practice having demonstrated that varnished wood is preferable to untreated orpainted wood, the tone quality varying somewhat with the particular I type of varnish used.

The type of varnish and mode vof finishing employed in the manufacture of high-grade violins and other wood string instruments being preferred.

Sound reproducers of the type mentioned are g'reatly improved in tone quality by the addition thereto of the above described attachment which eliminates harshness and undue prominence of tones or notes within one register over those of another higher or lower register contrary to the production of such tones or notes at the source. Forexample, the broadcasting of orchestral music substantially perfectly rendered is usually so reproducedat the receiving instruments as to render'either the high,middle or low-register tones or notes to be unduly prominent contrary to their prominence at the source. The attachment of this invention has been found to be very efiicient to effect correction of this fault probably because of the fact that the latter presents resonance members which are respectively more fully responsive to tonesor notes of different register than is the member 4 and thus coacts with the latter to better harmonize the ensemble and restore the broadcasted sound waves to more accurately accord with the source thereof.

-We claim as our invention: 1

1. An attachment of the type specified including a circular plate disposed over and spaced from the mouth of the sound-wave responsive member of the receiving instrument, a plate disposed substantially within the mouth of said member, and a circular plate disposed inwardly of and spaced from said second plate, there being annular spaces between the circumferential edges of said two last-mentioned plates and the wall of said member, and means rigidly associating said plates with each other and said first-named plate. 7

2. An attachment of the type specified including a circular plate disposed over and spaced from the mouth of the sound-wave responsive member of the receiving instrument, a plate disposed substantially within the mouth of said member, and a circular plate plate, said second plate being provided with a central opening of a diameter equal to substantially one-half the diameter of said plate. In testimony whereof, we have hereunto set our hands this 13th day of March, 1930.

ARNO E. TAUSCHER. BENNO E. SOHULTZE.

disposed inwardly of and spaced from said 7 second plate, there being annular spaces between the circumferentialedges of said two last-mentioned plates and the wall of said member, and means rigidly associating said plates with each other and said first-named 

